U.S. patent application number 13/207012 was filed with the patent office on 2011-12-08 for directional lead assembly.
This patent application is currently assigned to INTELECT MEDICAL, INC.. Invention is credited to Jesse GEROY, Scott KOKONES, John SWOYER.
Application Number | 20110301682 13/207012 |
Document ID | / |
Family ID | 40394118 |
Filed Date | 2011-12-08 |
United States Patent
Application |
20110301682 |
Kind Code |
A1 |
KOKONES; Scott ; et
al. |
December 8, 2011 |
DIRECTIONAL LEAD ASSEMBLY
Abstract
Leads having directional electrodes thereon. Also provided are
leads having directional electrodes as well as anchoring prongs to
secure the electrodes to the leads. Also provided are leads with
directional electrodes where all the electrodes have the same
surface area. Methods of treating conditions and selectively
stimulating regions of the brain such as the thalamus and
cerebellum are also provided.
Inventors: |
KOKONES; Scott; (Boston,
MA) ; SWOYER; John; (Andover, MN) ; GEROY;
Jesse; (North St. Paul, MN) |
Assignee: |
INTELECT MEDICAL, INC.
Boston
MA
|
Family ID: |
40394118 |
Appl. No.: |
13/207012 |
Filed: |
August 10, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
12029896 |
Feb 12, 2008 |
8019440 |
|
|
13207012 |
|
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Current U.S.
Class: |
607/148 |
Current CPC
Class: |
A61N 1/0551 20130101;
A61N 1/0529 20130101; A61N 1/0531 20130101; A61N 1/0539 20130101;
A61N 1/0534 20130101 |
Class at
Publication: |
607/148 |
International
Class: |
A61N 1/04 20060101
A61N001/04 |
Claims
1-26. (canceled)
27. An electrical lead comprising: a cylindrical lead body having
an outer surface, a proximal end, a distal end and a longitudinal
axis extending therethrough; and a plurality of directional
electrodes disposed on the distal end of the outer surface of the
cylindrical lead body, wherein the plurality of electrodes
comprises: a first pair of electrodes and a second pair of
electrodes, wherein the second pair of electrodes is rotated
relative to the first pair of electrodes.
28. The electrical lead of claim 27, wherein the second pair of
electrodes is rotated about 10.degree. to 90.degree. relative to
the first pair of electrodes.
29. The electrical lead of claim 27, wherein the first pair of
electrodes comprises a first electrode disposed about 180.degree.
relative to a second electrode, and the second pair of electrodes
comprises a third electrode disposed about 180.degree. relative to
a fourth electrode.
30. The electrical lead of claim 29, wherein the plurality of
electrodes further comprises: a third pair of electrodes comprising
a fifth electrode disposed about 180.degree. relative to a sixth
electrode.
31. The electrical lead of claim 30, wherein the plurality of
electrodes further comprises: a fourth pair of electrodes
comprising a seventh electrode disposed about 180.degree. relative
to a eighth electrode.
32. The electrical lead of claim 31, wherein the second pair of
electrodes is rotated 90.degree. relative to the first pair of
electrodes, the third pair of electrodes is rotated 90.degree.
relative to the second pair of electrodes, or the fourth pair of
electrodes is rotated 90.degree. relative to the third pair of
electrodes.
33. The electrical lead of claim 30, wherein the first pair of
electrodes and the third pair of electrodes are circumferentially
aligned.
34. The electrical lead of claim 31, wherein the second pair of
electrodes and the fourth pair of electrodes are circumferentially
aligned.
35. The electrical lead of claim 27, further comprising at least
one anchoring prong attached to or otherwise integral with each
directional electrode of the plurality of directional electrodes to
anchor the directional electrode to the cylindrical lead body.
36. An electrical lead comprising: a cylindrical lead body having
an outer surface, a proximal end, a distal end and a longitudinal
axis extending therethrough; and a plurality of directional
electrodes disposed on the distal end of the outer surface of the
cylindrical lead body, wherein the plurality of electrodes
comprises: a first electrode being disposed on a first side of the
lead body, and a second electrode being disposed on a second side
of the lead body, wherein the first electrode and the second
electrode are shifted longitudinally with respect to each
other.
37. The electrical lead of claim 36, wherein the first electrode is
disposed about 180.degree. relative to the second electrode.
38. The electrical lead of claim 37, wherein the plurality of
electrodes further comprises: a third electrode being disposed
about 180.degree. relative to a fourth electrode, wherein at least
a portion of the first electrode is longitudinally disposed
directly opposite a space between the second electrode and the
fourth electrode.
39. The electrical lead of claim 38, wherein the plurality of
electrodes further comprises: a fifth electrode being disposed
about 180.degree. relative to a sixth electrode, wherein at least a
portion of the third electrode is longitudinally disposed directly
opposite a space between the fourth electrode and the sixth
electrode.
40. The electrical lead of claim 39, wherein the first electrode,
the third electrode, and the fifth electrode are circumferentially
aligned on the first side of the lead body.
41. The electrical lead of claim 39, wherein the second electrode,
the fourth electrode, and the sixth electrode are circumferentially
aligned on the second side of the lead body.
42. The electrical lead of claim 36, wherein there is no spatial
pairing of the plurality of directional electrodes.
43. The electrical lead of claim 36, further comprising at least
one anchoring prong attached to or otherwise integral with each
directional electrode of the plurality of directional electrodes to
anchor the directional electrode to the cylindrical lead body.
44. An electrical lead comprising: a cylindrical lead body having
an outer surface, a proximal end, a distal end and a longitudinal
axis extending therethrough; a plurality of directional electrodes
disposed on the distal end of the outer surface of the cylindrical
lead body, wherein the plurality of electrodes comprises: a first
pair of electrodes and a second pair of electrodes, wherein the
first pair of electrodes comprises a first electrode disposed about
180.degree. relative to a second electrode, and the second pair of
electrodes comprises a third electrode disposed about 180.degree.
relative to a fourth electrode; and at least one cylindrical band
electrode disposed longitudinally between the first pair of
electrodes and the second pair of electrodes.
45. The electrical lead of claim 44, further comprising at least
one band electrode spaced proximally of the plurality of
directional electrodes.
46. The electrical lead of claim 44, further comprising at least
one anchoring prong attached to or otherwise integral with each
directional electrode of the plurality of directional electrodes to
anchor the directional electrode to the cylindrical lead body.
Description
FIELD OF INVENTION
[0001] The present invention provides an implantable or insertable
electrical lead having directional electrodes thereon.
BACKGROUND
[0002] Neuromodulation, such as deep brain stimulation, is becoming
an increasingly preferred form of therapy for certain neurological
conditions and disorders. Currently, deep brain stimulation of the
subthalamic nucleus and the globus pallidus interna is approved for
treatment of Parkinson's disease and deep brain stimulation of the
ventral intermediate nucleus is approved for treatment of essential
tremor. Other target sites in the brain to treat additional
disorders are also contemplated. For example, as described in U.S.
Pat. No. 5,938,688 and U.S. Pat. No. 6,167,311, respectively, the
intralaminar nuclei of the thalamus could be stimulated to treat
patients with impaired cognitive function and/or patients with
psychological disorders.
[0003] Current electrical leads used in deep brain stimulation,
however, do not provide precise targeting of the areas of the
thalamus such as the intralaminar nuclei, such that the desired
volume of tissue is stimulated. Accordingly, there is a need in the
art for a stimulation device that precisely targets specific
regions of the thalamus, maximizes stimulation of these specific
regions and minimizes stimulation of adjacent tissue that results
in undesirable side effects.
SUMMARY
[0004] In one embodiment, the present invention provides a lead
comprising a cylindrical lead body having a plurality of
directional electrodes on a distal end thereof. Preferably, the
plurality of directional electrodes are between four to twelve
electrodes. The cylindrical lead body further comprises at least
one anchoring prong attached to each electrode to anchor the
electrode to the cylindrical lead body.
[0005] In another embodiment, the present invention provides an
electrical lead comprising a cylindrical lead body having a
plurality of directional electrodes disposed on a distal end
thereof, wherein each one of the plurality of directional
electrodes has the same surface area.
[0006] In another embodiment, a lead has any one of, all of, or any
combination of the following features: a cylindrical lead body
having a diameter of about 0.70 millimeters (mm) to about 1.5 mm;
four to twelve directional electrodes disposed on the outer surface
of the cylindrical lead body; each electrode spanning about
90.degree. to about 150.degree. circumferentially around the body;
each electrode being radially spaced apart from an adjacent
electrode by 30.degree. to 180.degree.; each electrode being
axially spaced apart from an adjacent electrode by 0.25 mm to 2.00
mm; each electrode having a surface areas of between about 1
mm.sup.2 to 7 mm.sup.2; and each electrode having a length of about
0.75 mm to 3.0 mm. Preferably, the cylindrical lead body further
comprises at least one anchoring prong attached to each electrode
for anchoring the electrode to the cylindrical lead body.
[0007] In a preferred embodiment, the lead comprises a cylindrical
body having electrodes thereon that comprises any one of, all of,
or any combination of the following features: a cylindrical lead
body having a diameter of about 1.27 mm, eight electrodes disposed
on the outer surface of the cylindrical lead body; each electrode
spanning about 120.degree. circumferentially around the cylindrical
body; each electrode being radially spaced apart from an adjacent
electrode by 60.degree.; each electrode being axially spaced apart
from an adjacent electrode by 0.50 mm; each electrode having a
surface area of about 1.27 mm.sup.2; and each electrode having a
length of about 2.25 mm. The cylindrical lead body further
comprises at least one anchoring prong attached to each electrode
for anchoring the electrode to the cylindrical lead body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present invention will become more fully understood from
the detailed description given hereinbelow and the accompanying
drawings which are given by way of illustration only, and thus are
not limitative of the present invention, and wherein:
[0009] FIG. 1 is a fragmented schematic drawing of a distal end of
a lead with electrodes disposed thereon.
[0010] FIG. 2 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon.
[0011] FIG. 3 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon.
[0012] FIG. 4 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon.
[0013] FIG. 5 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon.
[0014] FIG. 6 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon.
[0015] FIG. 7 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon.
[0016] FIG. 8 shows an embodiment of an electrode with an anchoring
prong attached thereto.
[0017] FIG. 9 shows another embodiment of an electrode with
anchoring prongs attached thereto.
[0018] FIG. 10 shows another embodiment of an electrode with
anchoring prongs attached thereto.
[0019] FIG. 11 shows another embodiment of an electrode with
anchoring prongs attached thereto.
[0020] FIG. 12 shows another embodiment of an electrode with
anchoring prongs attached thereto.
[0021] FIG. 13 shows another embodiment of an electrode with
anchoring prongs attached thereto.
[0022] FIG. 14 is a diagrammatic view of a patient in which an
embodiment of a lead according to the present invention has been
implanted.
[0023] FIG. 15 is a fragmented schematic drawing of a distal end of
another embodiment of a lead with electrodes disposed thereon,
where the lead is shown as translucent in order to view the
electrodes on both sides of the lead.
DETAILED DESCRIPTION
[0024] The present invention provides electrical leads comprising a
cylindrical lead body having directional electrodes disposed on a
distal end thereof. As used herein, a "directional electrode"
refers to an electrode on a lead body, in which the electrode
extends less than 360.degree. about the lead body.
[0025] FIG. 1 shows an embodiment of electrical lead 10 comprising
a cylindrical lead body 20 having a plurality of directional
electrodes 30a-30h thereon. In FIG. 1, each electrode of a pair of
electrodes is disposed directly opposite from the other, on
opposing sides, first side 70 and second side 80, of the lead body
20. Additionally, the adjacent pairs can be aligned with each
other, as shown in FIG. 1 and FIG. 2, or rotated relative to each
other, as shown in FIG. 3.
[0026] FIG. 2 additionally shows an electrode 60 that can be
located on the distalmost tip of the lead body, and at least one
band electrode 50 can be provided near the proximal end of the lead
body 20. The distal electrode 60 can be one unitary electrode or
two separate electrodes and can be used for stimulating or sensing
in a region of the brain. The band electrode 50 is spaced away from
the directional electrodes 30, to provide for stimulation or
sensing in a region of the brain different from the region of the
brain to which the directional electrodes apply electrical
stimulation. For example, band electrode 50 can provide stimulation
or sense activity in the cortical region of the brain. Of course,
both a distalmost electrode and a proximal band electrode need not
be provided; the electrical lead body can include one or the other,
as shown in the below described embodiments.
[0027] FIG. 3 shows an electrical lead 10 with a first pair of
electrodes 30a and 30b being rotated 90.degree. relative to a
second pair of electrodes 30c and 30d (not visible in this view).
FIG. 3 also shows a third pair of electrodes 30e and 301 being
rotated 90.degree. relative to the second pair of electrodes 30c
and 30d, and thus being aligned with the first pair of electrodes
30a and 30b. Additionally, FIG. 3 shows a fourth pair of electrodes
30g and 30h (not visible in this view) being rotated 90.degree.
relative to the third pair of electrodes 30e and 30f, and thus
being aligned with the second pair of electrodes 30c and 30d.
Although a rotation of about 90.degree. is shown in FIG. 3, the
adjacent pairs can be rotated between about 10.degree. to
90.degree. relative to each other. Further, although in this
embodiment, electrode lead 10 has four pairs of electrodes, the
electrode lead 10 can have greater or fewer electrodes.
Additionally, in one embodiment, no electrode pairs are aligned
with each other, thus creating a spiral configuration, as shown in
FIG. 15.
[0028] The electrodes can also be arranged singly, as shown in FIG.
4 and FIG. 5. FIG. 4 is similar to the embodiment of FIG. 2,
however the electrodes 30a, 30c and 30e on the first side 70 of the
lead body 20 are shifted longitudinally with respect to the
electrodes 30b, 30d, 30f on the second side 80 of the lead body 20.
Thus, there is no pairing of the electrodes. The electrodes 30a,
30c, and 30e on the first side 70 of the lead body 20 are disposed
at least partially opposite the space between the electrodes on the
second side 80 of the lead body 20. Specifically, electrode 30a is
disposed opposite partial portions of electrode 30b and electrode
30d, and the entire space between electrode 30b and electrode 30d;
electrode 30c is disposed opposite partial portions of electrode
30d and electrode 30f, and the entire space between electrode 30d
and electrode 30f; and electrode 30e is disposed opposite electrode
30f and a partial portion of the space distal of electrode 30f. The
lead shown in FIG. 4 also includes two optional band electrode 50
near the proximal end of the lead body 20, which could be used, for
example, for sensing or stimulating the cortical region of the
brain. Of course these two band electrodes could also be disposed
on the other lead embodiments described herein.
[0029] FIG. 5 shows electrodes 30a-30f arranged singly, spaced
along the longitudinal axis. Each electrode can be rotated between
about 10.degree. to 90.degree. relative to each adjacent electrode
to provide for directed stimulation on only one side of the lead
body 20. Alternatively, the adjacent electrodes can be arranged in
a spiral configuration ascending the lead body 20.
[0030] FIG. 6 shows an electrical lead 10 with band electrodes 50
arranged in an alternating configuration between directional
electrodes 30. FIG. 6 is similar to the embodiment of FIG. 2,
however the second pair of directional electrodes 30c, 30d and the
fourth pair of directional electrodes 30g, 30h are both replaced by
band electrodes 50a, 50b. FIG. 6 shows two pair of electrodes
directional 30a, 30b and directional electrodes 30e, 30f, and two
band electrodes 50a, 50b between the pairs of directional
electrodes 30, a distalmost electrode 60, and a proximal band
electrode 50. However, the electrical lead 10 can have a different
number of directional electrode pairs and a different number of
band electrodes between the directional electrode pairs.
[0031] FIG. 7 shows an electrical lead 10 with directional
electrodes 30 on the first side 70 of the lead body 20 have a
length L that is greater than the length L of the directional
electrodes 30 on the second side 80 of the lead body 20.
Preferably, the length and radial spanning is modified such that
the surface area of each of the electrodes 30 is about 3 mm.sup.2.
FIG. 7 is similar to the embodiment of FIG. 2, however the two
electrodes 30a and 30c are replaced by one electrode 30i having a
length L that approximately equals (the length L of 30b)+(the
length L of 30d)+(the distance D between 30b and 30d) and the two
electrodes 30e and 30g are replaced by one electrode 30k having a
length L that approximately equals (the length L of 30f)+(the
length L of 30h)+(the distance D between 30f and 30h). Of course,
electrodes 30i and 30k could have other lengths as well and the
lead could have another number of electrodes disposed thereon.
[0032] As shown in FIG. 1 and FIGS. 8-13, in certain embodiments,
the cylindrical body includes at least one anchoring prong 41, 42,
43, 44 and/or 45 attached to or otherwise integral with each
electrode 30 that is encased in the lead body 20 during
manufacturing to anchor the electrodes 30 to the body 20.
Electrodes 30 can also be treated with a solvent, such as toluene
or DMAC, to aid in adhering to the lead body 20. The lead body 20
is preferably injection molded using polyurethane or other
biocompatible materials.
[0033] FIGS. 8-13 show different configurations of anchoring prongs
on the electrode 30. FIG. 8 shows an electrode 30 with one prong 41
at one end of one length side. FIG. 9 shows an electrode 30 with
two prongs 41, 42, one at each end of one length side. FIG. 10
shows an electrode 30 with one prong 41 at one end of one length
side and a second prong 43 at the center of the other length side.
FIG. 11 shows an electrode 30 with two prongs 41, 42, one at each
end of one length side and two prongs 44, 45 at the center of the
other length side. FIG. 12 shows an electrode 30 with one prong 43
at the center of one length side. FIG. 13 shows an electrode 30
with one prong 41, 42, one at one end of one length side and a
third prong 43 at the center of the other length side. Other
different permutations and combinations of anchoring prongs are
also contemplated. Preferably, each electrode has at least one
prong on each length side to prevent the electrode 30 from lifting
off of the electrode body 20.
[0034] In any of the embodiments described above, the size, shape,
configuration, and dimensions of the elongate lead will vary
depending upon the particular application. For example, the shape
of the elongate lead may be cylindrical, flat, conical, etc. Where
the elongate lead is cylindrical, the cylindrical lead body has a
diameter of about 0.70 mm to 1.5 mm. In a preferred embodiment, the
cylindrical lead body has a diameter of about 1.27 mm. Other
diameters are also possible, depending, for example, upon the
particular application.
[0035] Further, the material composition; electrical properties
(e.g., impedance); dimensions and configurations (such as, for
example, height, width, axial spacing, and shape); number; and
arrangement of the stimulation electrodes on the elongate lead will
vary depending upon the particular application. For example, the
electrodes may have a cylindrical shape, an oval shape, or a
rectangular shape. In fact, the individual electrodes may take any
variety of shapes to produce the desired focused and/or directional
electric field.
[0036] Regarding the number of electrodes, in certain embodiments,
the cylindrical body has four to twelve electrode disposed thereon.
In a preferred embodiment, the cylindrical body has eight
electrodes disposed thereon. The cylindrical lead body could also
have other numbers of electrodes disposed thereon.
[0037] As denoted in FIG. 1, each electrode is approximately
rectangular, having two length sides, each with a length L, and two
width sides, each with a width W, which is also referred to herein
as the "radial spanning." The length sides are approximately
parallel to the longitudinal axis of the cylindrical lead body and
the width sides are approximately perpendicular to the longitudinal
axis of the cylindrical lead body. In certain embodiments, the
length of each electrode is about 0.75 mm to 3.0 mm. In a preferred
embodiment, the length of the electrode is about 2.25 mm. Of
course, the electrodes could also have other dimensions. In certain
embodiments, the surface area of each electrode is between about 1
mm.sup.2 to 7 mm.sup.2. In a preferred embodiment, the surface area
of each electrode is about 3 mm.sup.2, such that the charge density
and safety calculations are the same for all electrodes. In other
particularly preferred embodiments, all the electrodes have the
same surface area irrespective of the particular shape or
configuration of the electrode. For example, in embodiments where
the cylindrical lead body has both cylindrical ring electrodes
disposed thereon and directional electrodes disposed thereon, in
this embodiment, the surface area of both types of electrodes are
the same. Of course, it is understood that each electrode does not
need to have the same surface area and certain electrodes can have
different surface areas.
[0038] As seen in the above-described embodiments, the directional
electrodes do not form a continuous electrode surface, but rather
the electrode surface is segmented into a plurality of individual
electrodes that are substantially isolated from each other.
Individual directional electrodes can range in an angular distance
around the exterior of the body of the elongate lead by as little
as a few degrees to almost completely around the body of the lead.
In certain embodiments, a directional electrode is curved around
the cylindrical body 10 so that the electrode radially spans
approximately 90.degree. to 150.degree. about the circumference of
the lead body 20 and each electrode is radially spaced apart from
an adjacent electrode by 30.degree. to 180.degree.. In a preferred
embodiment, the electrode extends about 120.degree. of the
circumference of the lead body and the electrodes are radially
spaced 60.degree. apart. Of course other configurations for the
radial span and radial spacing of the electrodes are also
contemplated.
[0039] Regarding the axial spacing of the electrodes, in certain
embodiments, the plurality of electrodes are spaced along the
longitudinal axis at a distance D, as denoted in FIG. 1, of 0.25 mm
to 2.00 mm from the next adjacent electrode. In a preferred
embodiment, the distance I) is about 0.5 mm. Other configurations
for the axial spacing between adjacent electrodes is also
contemplated. The electrodes can each be longitudinally spaced the
same distance apart or the distance between the electrodes can be
varied. Further, the electrodes can be disposed singly or in pairs
around the circumference of the lead body.
[0040] The material composition and mechanical properties (i.e. the
flexibility) of the body of the elongate lead will vary depending
upon the particular application. In some cases, the body of the
elongate body is formed of a non-conductive material, such as a
polymeric material, glass, quartz or silicone. In a preferred
embodiment, the elongate lead is fabricated from polyurethane.
[0041] The electrodes can be fabricated from a number of suitable
materials including platinum or titanium. In a preferred
embodiment, the electrodes are fabricated from platinum
iridium.
[0042] Electrical lead 10 can be implanted or inserted and removed
to modulate specific regions of the body. In certain embodiments,
the modulation includes ablation, stimulation and/or inhibition of
certain regions of the body. In a preferred embodiment, an
electrical lead is used to modulate a part of the nervous system,
including the brain and spinal cord. In a more preferred
embodiment, an electrical lead is used to modulate the brain. In
still another more preferred embodiment, an electrical lead is used
to modulate the thalamus 8, as schematically illustrated in FIG. 14
or the cerebellum. For example, activation of electrode 30 can
result in a volume of activation V that reaches the intralaminar
nuclei as well as parts of the lateral, medial and anterior
thalamus. Although the parameters of stimulation can depend on a
number of factors, in certain embodiments, a volume of activation
is generated by 3V, 90 microsecond, and approximately 50 hertz
stimulation.
[0043] Depending on the particular therapeutic application,
different electrodes 30 and/or different combinations of electrodes
30 on electrical lead 10 can be activated to provide different
directional modulation of specific regions brain, such as the
thalamus, and more particularly the lateral thalamus and/or the
medial thalamus as well as nuclei within the lateral and/or medial
thalamus, such as the intralaminar nuclei. Electrical lead 10 is
also capable of stimulating both the lateral and medial
thalamus.
[0044] Although not limited to any particular areas of the
thalamus, the electrical lead 10 of the present invention is
particularly useful for modulating the intralaminar nuclei, which
include, for example, the centromedial nucleus, the parafascicular
nucleus, the paracentral nucleus, the central lateral nucleus, and
the central medial nucleus. The electrical lead 10 may also be used
for preferential modulation of one side or the other side of nuclei
or a nucleus split by the internal medullary lamina.
[0045] Electrodes 30 of the present invention can have adjustable
power. For example, the pulsing parameters of the electrodes 30 may
be adjusted to initiate, stop, increase, or decrease the pole
combinations, energy, amplitude, pulse width, waveform shape,
frequency, and/or voltage or any other pulsing parameter known to
one of skill in the art to adjust the degree of modulation
delivered thereby. In a preferred embodiment, each electrode 30 of
body 20 of lead 10 is selectively controllable such that the
pulsing parameters of an electrode 30 can be adjusted independent
of the pulsing parameters of another electrode 30.
[0046] Referring to FIG. 14, the selective control over each
electrode 30 may be achieved by employing a system including a
programmer 520 coupled via a conductor 530 to a telemetry antenna
540. The programmer 520 is capable of sending signals via the
telemetry antenna 540 to control the electrical signal delivered to
electrodes 30. Such a system permits the selection of various pulse
output options after lead 10 is implanted using telemetry
communications. The present invention also contemplated
radio-frequency systems to selectively power electrodes 30.
[0047] As will be understood by one of skill in the art, the
independent control of each electrode 30 also provides a
practitioner with another means of modify or steer the direction of
stimulation since the locus of modulation can be selectively
adjusted to precisely target portions of the thalamus to achieve
the desired therapy. For example, electrode 30a may be powered to
modulate an area adjacent thereto while the signal to electrode 30c
may be substantially minimized to reduce or stop modulation to an
area adjacent to electrode 30c. Because the locus of modulation can
be selectively adjusted and/or steered in this embodiment of lead
10, specific target areas can be precisely targeted to achieve the
desired therapy. Other or additional means of selectively steering
electrical modulation may also be utilized in the present
invention, such as the methods described in U.S. Pat. No.
5,713,922, which is incorporated by reference herein.
[0048] A neural modulation delivery system including lead 10 to
modulate neural tissue to affect a neurological condition may
include other components useful in identifying, monitoring, or
affecting a specific site or a particular neurological condition
associated with the specific thalamic site. For example, such a
system could include a component for lesioning and temperature
monitoring, and/or a component that has a fiberoptic monitor which
allows telemetric intracranial monitoring capabilities, and/or a
microelectrode recording component, and/or a sensing component to
incorporate a feedback mechanism to assist in determining whether
lead 10 should be adjusted. With respect to a sensing component,
referring to FIG. 14, a sensor 550 can be incorporated with a
system of stimulating the thalamus, for example, according to the
present invention. Sensor 550 can be used with a closed-loop
feedback system in order to automatically determine the level of
stimulation necessary to provide the desired therapy. Sensor 550
may be implanted into a portion of a patient P's body suitable for
detecting characteristics, symptoms or attributes of the condition
or disorder being treated such as electrical brain activity,
cerebral blood flow, and/or vital signs or other chemical and
electrical activity of the body. Sensors suitable for use in a
system according to the present invention include, for example,
those disclosed in U.S. Pat. No. 5,711,316, which is incorporated
by reference herein. In cases where the attribute of the symptom is
the electrical activity of the brain, stimulating electrodes may be
intermittently used to record electrical activity. Alternatively,
one or more electrodes implanted within the brain may serve as a
sensor or a recording electrode. When necessary, these sensing or
recording electrodes may deliver modulation therapy to the
thalamus, for example. The output of an external feedback sensor
may communicate with an implanted pulse generator through a
telemetry down-link.
[0049] In order to advance lead 10 through a cannula, an actuator
system that creates linear motion may be provided. Lead 10 may be
provided within the cannula as part of the device or lead 10 may be
installed during the surgical technique. Preferably, lead 10 is
capable of being bent, capable of being pre-bent such that lead 10
has a memory bend, or capable of being pre-formed into a desired
shape that has memory. For example, lead 10 may be fabricated from
a shape memory alloy such as nitinol.
[0050] The present invention contemplates that electrical lead 10
is not only capable of being adjusted intra-operatively, but also
is capable of being adjusted post-operatively. Specifically, lead
10 positioning may be physically adjusted (advanced, retracted, or
moved to a different location) in the brain post-operatively
through the use of telemetry, RF signals, or other systems known in
the art. The cannula which is used to insert the lead need only be
inserted once while lead 10 may be repositioned in the brain tissue
multiple times to reach the desired area of the brain. Further,
electrodes 30 on lead 10 may be adjusted post-operatively by
turning them on or off, adjusting the voltage, adjusting the
frequency, and adjusting other electrical signal parameters through
the use of telemetry, RF signals, or other systems known in the
art. Those skilled in the art will appreciate that electrical
properties of the electrodes 30 and the resulting electrical field
may be varied by selectively powering individual or groups of
electrodes 30 formed from or controlled by micro-electrical
mechanical systems (MEMS). Moreover, MEMS actuators may drive
electrodes, drug delivery catheters, sensing probes, and the like
to the desired locations in an area of interest. Furthermore, lead
10 may also be used in conjunction with brain stimulation modeling
systems as described in U.S. Patent Publication No. 2006-0017749,
entitled "Brain Stimulation Models, Systems, Devices, and Methods",
which is incorporated by reference herein.
[0051] The leads of the present invention can be used to treat a
variety of medical conditions such as, for example, chronic pain,
psychiatric disorders, traumatic brain injury, stroke and the
present invention provides for such methods. For example, in
certain embodiments a method of treating a medical condition
comprises inserting or implanting an electrical lead according to
an embodiment of the present invention in a target site of the body
and selectively activating one or more of the directional
electrodes to provide targeted stimulation of the target site.
Further diseases are mention in co-pending U.S. utility application
Ser. No. 11/871,727, filed on Oct. 12, 2007, which is incorporated
by reference herein.
[0052] The foregoing description and examples have been set forth
merely to illustrate the invention and are not intended as being
limiting. Each of the disclosed aspects and embodiments of the
present invention may be considered individually or in combination
with other aspects, embodiments, and variations of the invention.
Further, while certain features of embodiments of the present
invention may be shown in only certain figures, such features can
be incorporated into other embodiments shown in other figures while
remaining within the scope of the present invention. In addition,
unless otherwise specified, none of the steps of the methods of the
present invention are confined to any particular order of
performance. Modifications of the disclosed embodiments
incorporating the spirit and substance of the invention may occur
to persons skilled in the art and such modifications are within the
scope of the present invention. Furthermore, all references cited
herein are incorporated by reference in their entirety.
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